Since I pass to Beta 3 I have the following error:
[ERROR] Errors in 'jar:file:/D:/gwt/gxt-1.0-Beta3/gxt.jar!/com/extjs/gxt/ui/client/fx/Fx.java'
[ERROR] Line 15: The import com.google.gwt.user.client.animation cannot be resolved
[ERROR] Line 54: Animation cannot be resolved to a type
[ERROR] Line 58: animation cannot be resolved
[ERROR] Line 58: Animation cannot be resolved to a type
...